SCSI Port Error with Tape Backup

I am running ARCserve 2000 Advanced edition with the Compaq 20/40-GB DAT 8 Cassette Tape autoloader on my ProLiant 2500 server (Win NT - SP5). I am continually getting an error in both the event log and the tape log from cpq32fs2 saying that "The device, \Device\ScsiPort 3, is not ready for access yet.". This happens sporatically and sometimes I can get a full back while other times only a partial backup. Can anyone offer some suggestions on what to do to get this fixed? Thanks!

Re: SCSI Port Error with Tape Backup

The DAT tape drive is a slower SCSI device. The SCSI bus has to change speeds anytime the tape drive is accessed. If the tape backup software sends a SCSI command to the SCSI controller while the SCSI bus is changing speed, you will get the device not ready error message. After the SCSI bus has changed speeds the SCSI command should be resent by the backup. If not, the backup software is not allowing enough time for the SCSI bus to change speed. This can cause the backup to time out and the backup job is aborted by the backup software.

There are two possible solutions for this type of backup problem.

1. Upgrade the backup software to a newer version that allows for the required SCSI bus speed changes.

2. Put the tape drive on a dedicated SCSI controller so that the SCSI bus does not have to change speed. This will also give maximum backup performance because the first SCSI controller is reading the data from the hard drives while the 2nd SCSI controller is writing to the tape.